Heterometallic Multiple Bonding: Delocalized Three-Center σ and π Bonding in Chains of 4d and 5d Transition Metals

Abstract

Heterotrimetallic compounds Mo2Ru(dpa)4Cl2 (1) and W2Ru(dpa)4Cl2 (2) are prepared by reactions of M2(dpa)4 (M = Mo or W; dpa = 2,2'-dipyridylamide) with [Ru(CO)3Cl2]2. Crystallographic studies reveal short Mo-Ru and W-Ru distances, 2.38 Å (1) and 2.39 Å (2), suggestive of delocalized Mo-Mo-Ru and W-W-Ru bonding. In contrast to the σ bonding found in the corresponding iron compounds, density functional theory calculations reveal both a three-center/two-electron σ bond and two three-center/four-electron π bonds in the M-M-Ru compounds.

Electron Delocalization of Mixed‐Valence Diiron Sites Mediated by Group 10 Metal Ions in Heterotrimetallic Fe‐M‐Fe (M=Ni, Pd, and Pt) Chain Complexes

“…It should be noted that a ratio of 1:6 (Ni II /Fe II ) was used to avoid the formation of the homotrinickel string complex. For the preparation of 2 and 3 , [MCl 2 (MeCN) 2 ] salts (M=Pd and Pt) were used, replacing the corresponding anhydrous salts MCl 2 for ease of synthetic operations . Compound 2 was prepared based on similar synthetic procedures as those for 1 , whereas an extended reaction time (≈3 h) was applied.…”

“…After that, the resultingm ixture was cooled and treated with hexane to dissolve naphthalenea nd to precipitate the target product, which was further extracted by CH 2 Cl 2 .I ts hould be noted that ar atio of 1:6( Ni II /Fe II )w as used to avoid the formationo ft he homotrinickel string complex.F or the preparation of 2 and 3, [MCl 2 (MeCN) 2 ]s alts (M = Pd and Pt) were used, [19] replacing the corresponding anhydrous salts MCl 2 for ease of synthetic operations. [20] Compound 2 was prepared based on similars ynthetic procedures as those for 1,w hereas an extended reaction time ( % 3h)w as applied. The directs ynthesis of 3 requires a prolonged time ( % 6h), which may lead to the decomposition or oxidation of Fe II and consequently,l owers the reaction yield.…”

From Homonuclear Metal String Complexes to Heteronuclear Metal String Complexes

“…[45] [MoMoRu(dpa) 4 Cl 2 ] (44) and [WWRu(dpa) 4 Cl 2 ] (45) represent the first HMSCs that do not contain first-row transition metals. [46] Crystallographic studies reveal very short Mo-Ru and W-Ru distances of 2.38 and 2.39 Å, respectively, which suggest significant electron delocalization along the M-M-Ru chain. DFT calculations show that a 3c-2e σ bond and two 3c-4e π bonds contribute to the electronic structure.…”

Coordination Chemistry of 2,2’-Dipyridylamine: The Gift That Keeps on Giving

“…[77] This series was recently expanded to include Mo 2 Ru(dpa) 4 Cl 2 and W 2 Ru(dpa) 4 Cl 2 , the first heterometallic EMAC compounds not to include a first-row transition metal, Figure 17, for which heterometallic π bonding is also observed. [82] Oxidation of Mo 2 Ru(dpa) 4 Cl 2 to the corresponding cation,…”

“…X-ray crystal structure of Mo 2 Ru(dpa) 4 Cl. [82] Blue spheres represent nitrogen and black spheres represent carbon. Hydrogen atoms have been omitted.…”